1 files changed, 105 insertions, 0 deletions
diff --git a/tests/selenium/fingerprinting_test.py b/tests/selenium/fingerprinting_test.py
new file mode 100644
index 0000000..0fadd2b
--- /dev/null
+++ b/tests/selenium/fingerprinting_test.py
@@ -0,0 +1,105 @@
+#!/usr/bin/env python
+# -*- coding: UTF-8 -*-
+
+import unittest
+
+import pbtest
+
+from functools import partial
+
+from pbtest import retry_until
+
+
+class FingerprintingTest(pbtest.PBSeleniumTest):
+    """Tests to make sure fingerprinting detection works as expected."""
+
+    def detected_fingerprinting(self, domain):
+        return self.js("""let tracker_origin = window.getBaseDomain("{}");
+let tabData = chrome.extension.getBackgroundPage().badger.tabData;
+return (
+  Object.keys(tabData).some(tab_id => {{
+    let fpData = tabData[tab_id].fpData;
+    return fpData &&
+      fpData.hasOwnProperty(tracker_origin) &&
+      fpData[tracker_origin].canvas &&
+      fpData[tracker_origin].canvas.fingerprinting === true;
+  }})
+);""".format(domain))
+
+    def detected_tracking(self, domain, page_url):
+        return self.js("""let tracker_origin = window.getBaseDomain("{}"),
+  site_origin = window.getBaseDomain((new URI("{}")).host),
+  map = chrome.extension.getBackgroundPage().badger.storage.snitch_map.getItemClones();
+
+return (
+  map.hasOwnProperty(tracker_origin) &&
+    map[tracker_origin].indexOf(site_origin) != -1
+);""".format(domain, page_url))
+
+    def get_fillText_source(self):
+        return self.js("""
+            const canvas = document.getElementById("writetome");
+            const ctx = canvas.getContext("2d");
+            return ctx.fillText.toString();
+        """)
+
+    def setUp(self):
+        # enable local learning
+        self.load_url(self.options_url)
+        self.wait_for_script("return window.OPTIONS_INITIALIZED")
+        self.find_el_by_css('#local-learning-checkbox').click()
+
+    # TODO can fail because our content script runs too late: https://crbug.com/478183
+    @pbtest.repeat_if_failed(3)
+    def test_canvas_fingerprinting_detection(self):
+        FIXTURE_URL = (
+            "https://efforg.github.io/privacybadger-test-fixtures/html/"
+            "fingerprinting.html"
+        )
+        FINGERPRINTING_DOMAIN = "cdn.jsdelivr.net"
+
+        # clear pre-trained/seed tracker data
+        self.load_url(self.options_url)
+        self.js("chrome.extension.getBackgroundPage().badger.storage.clearTrackerData();")
+
+        # visit the page
+        self.load_url(FIXTURE_URL)
+
+        # now open a new window (to avoid clearing badger.tabData)
+        # and verify results
+        self.open_window()
+
+        # check that we detected the fingerprinting domain as a tracker
+        self.load_url(self.options_url)
+        # TODO unnecessary retrying?
+        self.assertTrue(
+            retry_until(partial(self.detected_tracking, FINGERPRINTING_DOMAIN, FIXTURE_URL)),
+            "Canvas fingerprinting resource was detected as a tracker.")
+
+        # check that we detected canvas fingerprinting
+        self.assertTrue(
+            self.detected_fingerprinting(FINGERPRINTING_DOMAIN),
+            "Canvas fingerprinting resource was detected as a fingerprinter."
+        )
+
+    # Privacy Badger overrides a few functions on canvas contexts to check for fingerprinting.
+    # In previous versions, it would restore the native function after a single call. Unfortunately,
+    # this would wipe out polyfills that had also overridden the same functions, such as the very
+    # popular "hidpi-canvas-polyfill".
+    def test_canvas_polyfill_clobbering(self):
+        FIXTURE_URL = (
+            "https://efforg.github.io/privacybadger-test-fixtures/html/"
+            "fingerprinting_canvas_hidpi.html"
+        )
+
+        # visit the page
+        self.load_url(FIXTURE_URL)
+
+        # check that we did not restore the native function (should be hipdi polyfill)
+        self.assertNotIn("[native code]", self.get_fillText_source(),
+            "Canvas context fillText is not native version (polyfill has been retained)."
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()